Pulse Oxymetry

Pulse oximetry is a noninvasive method for monitoring a person's oxygen saturation. Peripheral oxygen saturation (SpO2) readings are typically within 2% accuracy (within 4% accuracy in the worst 5% of cases) of the more desirable (and invasive) reading of arterial oxygen saturation (SaO2) from arterial blood gas analysis.

1. Pulse Oximetry MR.J.G Sambad (M.Sc.Nursing-M.S.N)

2. Pulse Oximeter: Pulse Oximeter used to measure oxygen saturation in the body i.e how much of the hemoglobin in the blood is carrying the oxygen.

3. DEFINITION IT IS A NON INVASIVE DEVICE USED TO MEASURE BLOOD OXYGEN LEVELS AND CAN ALSO DISPLAY HEART RATE. A PULSE OXIMETER IS A MEDICAL DEVICE THAT INDIRECTLY MONITORS THE OXYGEN SATURATION OF A PATIENT'S BLOOD

4. PURPOSES OF PULSE OXYMETRY: PULSE OXYMETERS MEASURE THE ARTERIAL OXYGEN SATURATION OF HAEMOGLOBIN. TO RELIEVE CYANOSIS BY DETECTING HYPOXIA AND SEVEOUR RESPIRATORY FAILURE. PULSE OXIMETERS MEASURE: THE OXYGEN SATURATION OF HAEMOGLOBIN IN ARTERIAL BLOOD THE PULSE RATE - IN BEATS PER MINUTE

5. Calculation:

6. FUNCTIONS Q IT IS A SAFE AND SIMPLE METHOD OF ASSESSING OXYGENATION. Q IT IS NONINVASIVE. Q ACCEPTABLE NORMAL RANGES ARE FROM 95 TO 100 PERCENT. Q CONVENIENT ANDMEASUREMENT CAN BE CONTINOUS.

7. Pulse Oximeters may be used in patients: Undergoing surgical procedure under general anesthesia Undergoing surgical procedure under conscious sedation

8. Pulse Oximeters may be used in patients: Emergency situations like loss of consciousness, trauma etc. After surgery during the recovery phase In the ICU, Pulse Oximetry is used extensively on mechanically ventilated patients

9. Pulse Oximeters may be used in patients: Pulse Oximeters are routinely used in certain hospital wards and in casualty departments for immediate assessment of patients

10. Pulse Oximeter reading may not be accurate Venous congestion (partial obstruction of the veins) of an arm or leg Reduced peripheral pulsatile blood flow Bright overhead lights, such as in an operating theatre Shivering or significant, repeated movement of the sensor

11. Pulse Oximeter reading may not be accurate: Nail varnish may cause falsely low readings with most pulse Oximeters, especially those colored blue or black

12. The following won’t affect the Pulse Oximeter reading: Anemia Jaundice

13. OXIMETERS CONSIST OF ☺ PERIPHERAL PROBE ☺ A MICROPROCESSOR UNIT DISPLAYS A WAVEFORM, THE OXYGEN SATURATION AND THE PULSE RATE. ☺RED AND INFRARED ☺ LIGHT EMITERS DETECTOR MOST OXIMETERS ALSO HAVE AN AUDIBLE PULSE TONE,

14. Operation: F inger is placed in between the light source and the light detector. Non absorbed light by finger reaches at detector. Light is emitted from light sources which goes across the pulse oximeter probe and reaches the light detector .

15. The amount of light absorbed depends on three physical properties: 1 . concentration of the light absorbing substance. 2. length of the light path in the absorbing substance 3. oxyhemoglobin and deoxyhemoglobin absorbs red and infrared light differently

16. Property No.1 Amount of light absorbed is proportional to the concentration of the light absorbing substance.

17. Property No.2 Amount of light absorbed is proportional to the length of the light path.

18. Property No.3 oxyhemoglobin absorbs more infrared light than red light & deoxyhemoglobin absorbs more red light than infrared light.

19. PRINCIPLES OF PULSE OXIMETRY TECHNOLOGY A IT IS BASED ON THE RED AND INFRARED LIGHT ABSORPTION CHARACTERISTICS OF OXYGENATED AND DEOXYGENATED HEMOGLOBIN. A RED LIGHT IS IN THE 600-750 NM WAVELENGTH LIGHT BAND. INFRARED LIGHT IS IN THE 850-1000 NM WAVELENGTH LIGHT BAND.

20. PULSE OXIMETRY WORKS BY PLACING A PULSATING ARTERIOLAR VASCULAR BED BETWEEN A DUAL LIGHT (RED AND INFRARED) SOURCE AND A PHOTODETECTOR. THE PHOTODETECTOR RECORDS THE RELATIVE AMOUNT OF EACH COLOR ABSORBED BY ARTERIAL BLOOD AND TRANSMITS THE DATA TO A MONITOR, WHICH DISPLAYS THE INFORMATION WITH EACH HEARTBEAT.

21. GENERALLY MEASURED ON: VARIOUS SITES LIKE THE FINGER Y TOE Y PINNA (TOP) OR LOBE OF THE EAR Y INFANTS - THE BRIDGE OF THE NOSE,FOOT OR PALM OF THE HAND, THE BIG TOE OR THE THUMB.

22. TYPES OF OXIMETERS Designs: Pulse Oximeter as part of an anesthetic machine A portable desktop unit A finger/mobile pulse Oximeter

23. Pulse Oximeter as part of an anesthetic machine

24. Pulse Oximeters (continue) Desktop Finger/mobile

25. Types

26. ADVANTAGES A PULSE OXIMETER IS USEFUL IN ANY SETTING WHERE A PATIENT'S OXYGENATION IS UNSTABLE: a INCLUDING INTENSIVE CARE UNITS (SICU, CTICU, PICU, NICU. a OPERATION THEATRE AND RECOVERY ROOMS. a E MERGENCY OR CAUSALITY. HOSPITAL WARD SETTINGS AND DETERMINING THE EFFECTIVENESS OF NEED FOR SUPPLEMENTAL OXYGEN

27. 1) OXIMETRY IS NOT A COMPLETE MEASURE OF RESPIRATORY SUFFICIENCY. A PATIENT SUFFERING FROM HYPOVENTILATION (POOR GAS EXCHANGE IN THE LUNGS ) GIVEN 100% OXYGEN CAN HAVE EXCELLENT BLOOD OXYGEN LEVELS WHILE STILL SUFFERING FROM RESPIRATORY ACIDOSIS DUE TO EXCESSIVE CARBON DIOXIDE. LIMITATIONS

28. 2) IT IS ALSO NOT A COMPLETE MEASURE OF CIRCULATORY SUFFICIENCY IF THERE IS INSUFFICIENT BLOODFLOW OR INSUFFICIENT HEMOGLOBIN IN THE BLOOD ( ANEMIA ), TISSUES CAN SUFFER HYPOXIA DESPITE HIGH OXYGEN SATURATION IN THE BLOOD THAT DOES ARRIVE

29. 3) A HIGHER LEVEL OF METHEMOGLOBIN WILL TEND TO CAUSE A PULSE OXIMETER TO READ CLOSER TO 85% REGARDLESS OF THE TRUE LEVEL OF OXYGEN SATURATION. 4) IT WILL NOT SHOW THE PCO2 AND ACID BASE STATUS. 5) IT WILL NOT PROVIDE AN ABSOLUTE INDICATOR OF HYPEROXIA.

30. IN ACCURATE RESULTS IN FOLLOWING CONDITIONS E POOR PERFUSION ( PROCESS OF NUTRITIVE DELIVERY OF ARTERIAL BLOOD TO A CAPILLARY BED IN THE BIOLOGICAL TISSUE ). E DYSHAEMOGLOBIN (OR)CARBOXYHEMOGLOBIN Is a stable complex of carbon monoxide and hemoglobin that forms in red blood cells when carbon monoxide is inhaled or produced in normal metabolism.

31. E HYPER OXYGENATION E ARRHYTHMIA : it is An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm, such as beating too fast (tachycardia), too slow ( bradycardia ), or irregularly. E EXCESSIVE AMBIENT LIGHT

32. A PULSE OXIMETER GIVES NO INFORMATION ON ANY OF THESE OTHER VARIABLES d THE OXYGEN CONTENT OF THE BLOOD. d THE AMOUNT OF OXYGEN DISSOLVED IN THE BLOOD. d THE RESPIRATORY RATE OR TIDAL VOLUME I.E. VENTILATION. d THE CARDIAC OUTPUT OR BLOOD PRESSURE.

33. PROVIDE THE PATIENT WITH A SIMPLE EXPLANATION OF PULSE OXIMETRY AND ITS VALUE. SELECT APPROPRIATE SENSOR PROBE FOR PATIENT’S AGE, WEIGHT, CONDITION, DURATION OF PULSE OXIMETRY MONITORING, AS WELL AS THE USE OF BP CUFF, ARTERIAL CATHETER AND/OR PERIPHERAL I.V. LINE. NURSING RESPONSIBILITIES

34. REMOVE ANY NAIL POLISH FROM ANY DIGITS WHICH WILL HAVE A SENSOR APPLIED AS IT INTERFERES WITH LIGHT TRANSMISSION IF IT SHOWS WRONG READING CHECK PATIENT’S BP AND VITAL SIGNS FIRST – IF THEY ARE ACCEPTABLE FOR PATIENT, THEN CHECK FOR THE FOLLOWING. Bad Connection Inadequate or Intermittent Blood Flow to Site Equipment Malfunctions

35. AFTER USE: REMOVE SENSOR FROM MONITORING SITE. WASH SITE OFF WITH SOAP AND WATER. (DO NOT USE ALCOHOL). DOCUMENTATION : DOCUMENT PULSE OXIMETER READINGS (SAO2), SENSOR PLACEMENT AND ALARM SETTINGS (CONTINUOUS MODE) ON PATIENT CARE RECORD OR FLOWSHEET.

36. THANK YOU